Design And Implementation Of Weather Facsimile Receiver Based On CPCI

Weather facsimile receiver can receive facsimile charts broadcasted by coast stations and getmeteorological condition of the sea region, which can be used to ensure a safe navigation. Analogdevices are extensively used in current Weather facsimile receivers, thus facsimile machines are bulky,high power consumption, and the use of analog devices have detrimental effect on the miniaturization ofthe receiver. Analog Devices also cause poor performance of system maintenance and the wholeperformance is greatly affected by distinction in individual performance and environmental factors.Other shortcomings include higher cost and longer hardware debugging process.The design of receiver based on CPCI is developed for the shortcomings of existing receivers. ThisReceiver includes three parts: the RF front-end processing module, the digital signal processing unit andan image processing system.The designed Weather facsimile receiver uses a super-heterodyne architecture scheme. RFfront-end processing module is responsible for RF signal filtering, amplification, mixing. Three times ofmixing is applied in the circuit and the total gain is reasonably assigned to several steps in signalprocessing. Self testing circuit would carry out self test of software and hardware in the system.In digital signal processing unit, DSP is used as the controller and the signal processor. Basebanddemodulation is achieved through software which simplifies the design of hardware, reduces the noiseof analog devices and at the same time enhances the level of digitalization of the system.Image processing system accomplish man-machine interaction, image display and data storage.The use of CPCI makes the system perform well in use range, heat dissipating, shock resistance,maintainability, bus transmission speed and expandability. These characteristics make the system moresuitable for ship.The paper presented the parameters of the system and analyzed the methods of design of eachcircuit unit. After the circuit boards is manufactured and debugged, the paper tested the system and theresult proved that the system design is feasible.